Linus Torvalds writes: (Summary) It's the low-volume stuff that
almost nobody uses and where the customer is used to the whole notion
of boutique hardware, so they're used to having to do special things
for special hardware.
for special hardware.
And I very much use the word "special" in the "my mom told me I was special" sense. Particularly if the memory area (source or dest) might be unaligned.
(source or dest) might be unaligned.
The rule of thumb should be: don't use PIO, and if you *do* use PIO, don't be picky about what you get.
don't be picky about what you get.
And most *definitely* don't complain about performance to software people. Get a competent piece of hardware, or a competent hardware designer.
or a competent hardware designer.
Let's face it, PIO is stupid.
for special hardware.
And I very much use the word "special" in the "my mom told me I was special" sense. Particularly if the memory area (source or dest) might be unaligned.
(source or dest) might be unaligned.
The rule of thumb should be: don't use PIO, and if you *do* use PIO, don't be picky about what you get.
don't be picky about what you get.
And most *definitely* don't complain about performance to software people. Get a competent piece of hardware, or a competent hardware designer.
or a competent hardware designer.
Let's face it, PIO is stupid.